Internal combustion engine



Aug. 28, 1934. J. H, MERCE l1,971,620

INTERNAL COMBUSTION ENGINE Original Filed July 5, 1928 2 Sheets-Sheet 1 l BY ORNEY Aug. 28, 1934. H MERCE 1,971,620

INTERNAL COMBUSTION ENGINE Original Filed July 5, 1928 2 Sheets-Sheet 2 INVENTOR J'ames /f Puerca Patented Aug. 28, 1934 UNITED STATES 1,971,620 INTERNAL COMBUSTION ENGINE James H. Pierce, Bay City, Mich.

Original application July 5,

1928, Serial No.

290,563, now Patent No. 1,910,561, dated May 23,

1933. Divided and this application January 1931, Serial No. 506,009. In Great Britain July 1o claims.

This invention relates to internal combustion engines and is a division of my application for Letters Patent of the United States for Improvements in marine propulsion, led July 5, 1928, and serially-Numbered 290,563, now Patent No. 1,910,561, May 23, 1933.

The objects of the present invention are to provide an internal combustion Vengine having certain new and novel features of construction; to provide a new and novel oiling system for internal combustion engines; to providean internal combustion engine of the two-cycle type lhaving novel means for controlling the flow of combustible mixture into the crank case thereof; and to provide a piston of new and novel construction for internal combustion engines of the two-cycle type.

Other objects are to provide an internal combustion engine of a type particularly suitable for use in connection with outboard motors; to provide a new and novel means for supporting the Weight of the engine crank shaft in an out- `board motor; and to provide a new and novel crank shaft construction for internal combustion engines having vertically disposed crank shafts. Y The above being among the objects of the present invention, the same consists in certain features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawings, and then claimed, having the above and other objects in View.

In the accompanying drawings, which illustrate a suitable embodiment of the present invention and in which like numerals refer to like parts throughout the several different views:

Fig. l is a side elevational view of an outboard motor.

Fig. 2 is a fragmentary, partially broken, vertical section'al view taken axially through the power shaft housing of the outboard motor shown in Fig. l in a plane parallel to the plane of the drawings, and illustrating the construction of the outboard motor at the point where the upper and lower portions of the power shaft housing are joined together.

Fig. 3 is a vertical sectional View taken through .the axes of the crank shaft and cylinders of the internal combustion engine shown mounted on the outboard motor in Fig. 1, certain parts being broken away, and other parts being shown in section to better illustrate the construction.

Fig. 4 is a sectional View through one of the cylinders, and the piston contained therein, taken on the line 4 4 of Fig. 3.

i Fig. 5 is a plan view of .the lower end of the (Cl. 12S- 56) crank case, or crank case cover of the engine shown in Fig. 3.

Fig. 6 is a plan view ofthe disc valve employed for controlling the ilow of mixture into the crank case of the engine shown in the previous views, a portion of the crank shaft being shown in connection therewith to illustrate its relation thereto during rotation of the crank shaft in one direction.

Fig. 7 is a View similar to Fig. 6 but illus- 5 trating the position of the crank shaft in respect to the disc valve when the crank shaft `is r0 tated in a direction opposite to that shown in Fig. 6.

Fig. 8 is an enlarged fragmentary vertical sectional view taken through the edge of the crank case cover at the point thereon where the lubricating oil is tapped out of the crank case to be led to the engine bearings.

Fig. 9 is a View similar to Fig. 8 but showing 7'5 a slightly modied construction.

Fig. l0 is a fragmentary sectional view taken on the line 10-10 of Fig. 8.

I show in Fig. 1 an outboard motor comprising generally an engine'having a crank case 25 and cylinders 26, a drive shaft housing comprising an upper section 27 and a lower section 28, the latter of which terminates at its lower end in a housing portion' 29 enclosing a propeller shaft (not shown) the ends of which project both for? wardly and rearwardly from the housing portion 29 and to the forwardly extending portion of which is suitably secured a, propeller 30 and to the rearwardly extending portion of which is suitably secured a propeller 31.

For supporting the outboard motor from a boat, the upper drive shaft portion 27 is provided with a pair of spaced radial anges 32 and 33 between which is received the two-part sleeve 34 rotatably embracing the portion 27 and provided with an extension arm 35 rotatably received on the pin 36, which, in turn, is secured in a bracket member 37 provided with clamping means 38 enabling the bracket to be clamped to the transom 39 of. a boat.

The engine may be provided with a muilier 111 as in conventional constructions together with a steering handle 184, together with a spark control lever 185 which may be connected to a magneto (not shown) housed within the usual iiywheel 188. A fuel tank 186 may be supported from the engine in any suitable manner.

As indicated best in Figs. 1 and 3, the upper end of the upper housing section 27 is formed with an enlarged flange 90 which serves as a cap or cover for the lower face of the crank case 25 110 and which serves to support'l the engine thereon. As shown in Figs. 3 to 10 inclusive, the engine is of the two-cycle type having a pair of opposed cylinders 26 which are secured to the crank case 25 by bolts 92 and nuts 93. The combustible mixture is drawn into the crank case through a carburetor 94, which may be of any conventional construction, and through the duct 95 which opens into the crank case through the segmental opening 96 in the cover 90. The crank shaft 97 is of the two-throw type having bearing in the bushings 98 and 99 carried by the housing section 27 and crank case extension 100 respectively. The lower end of the crank shaft 97 is hollow as at 101 and is splined as at 102 for connection to the upper end of the upper drive shaft section 44 which is splined to cooperate therewith. Each of the cylinders 26 is provided with a piston 103 which is connected to its corresponding crank shaft throw by a connecting rod 104 and piston pin 105. Each piston is provided with a port 106 in its side wall through which the combustible mixture compressed in the crank case passes to the by-pass 107 (see Fig. 4) when the piston is at and near the bottom of its stroke, in order to enter the cylinder 91 above the piston. The burned gases in the cylinders escape through the ports 108 into the passages 109 where they are led into the exhaust pipes 110 and thence to the mufller 111 in the conventional manner.

In view of the high speeds at which it is desirable to operate an engine of the type shown, and to reduce Vibration, it is desirable that the pistons 103 be of as light construction as possible, and it is therefore desirable that such pistons be constructed of a light metal such as aluminum or one of the alloys thereof. In the preferred construction of pistons for two-cycle engines, deflecting bailles such as 112 are provided. These baiiles are relatively difficult to cool, and heretofore when pistons equipped with such baffles have been constructed of light metal having a relatively low melting point, the baffles have. often been burned oi at high engine speeds and full load. In accordance with the present invention I provide a construction for such pistons which insures cooling of the piston head to such a degree as to obviate any possibility of damage to the baffles 112 due to the excessive heat, and at the same time I am enabled to heat the combustible mixture entering the cylinder an amount commensurate With optimum engine operating conditions. This is accomplished in the following manner as illustrated in Figs. 3 and 4: extending downwardly from the top of the piston 103 in parallel and spaced relationship and in a direction perpendicular to the side of the piston on which the port 106 opens, is a plurality of webs 113 which extend to a point spaced from the outer ends of the connecting rods 104. Extending diametrically across the piston between the lower ends of the Webs 113 and the outer end of the cooperating connecting rod and perpendicular tothe planes of the Webs 113 is a l baille 114 which extends into relatively close relationship with respect to the corresponding end of the connecting rod. A third baille 115, best illustrated in Fig. 4, extends from the inner edge of the port 106 into relatively close relationship with the corresponding end of the connecting rod 104. The result of this construction is that as the engine is operating and combustible mixture is drawn into the crank case 25 on the outstroke of the pistons and compressed therein on the instroke thereof, when the pistons reach the inner end of their stroke, the compressed combustible mixture in the crank case is forced through the piston and out of the port 106 into the by-pass 107 and thence into the cylinder. In passing through each piston, the baille 115 causes the combustible mixture to pass through the piston on the opposite side of the piston pin 105 from the baille 115, and in passing over the piston pin and outer end of the connecting rod, the baille 114 directs the combustible mixture up-over the same and between the webs 113, which, being cast integrally with the head of the piston, rapidly conduct the heat therefrom. After passing through the webs 113 the combustible mixture may escape through the port 106 into the by-pass 107, as described. i

In this manner substantially all-the combustible mixture entering the cylinders is forced to pass up into closely adjacent relationship with-respect to the head of the corresponding piston and takes up heat-therefrom as Well as from the ribs 113 connected thereto. This insures such a rapid transfer of heat from the bafes 112 that the same are prevented from reaching a temperature which may be detrimental to them. Furthermore, I have found that this construction maintains the head of the piston at a temperature below that at which the hydro-carbons in the crank case, and which may find their way into contact with the head of the piston, are sufficiently heated to cause cracking thereof and subsequent depositing of free carbon on the under side of the piston head.

Another feature of the present invention is the valvular means provided for regulating the admittance of combustible mixture through the duct 95 into the crank case. As is well-known in the art, the usual method of introducing combustible mixture into the crank case of a two-cycle engine is either through a check valve placed in the passage between the crank case and the carburetor, or by a port through the cylinder controlled by the movement of the piston during its travel, or by a combination of both.

.The employment of a check valve is undesirable because of the relatively delicate construction of the same necessary for high engine speeds and the spring means which must be employed in connection with it, the tension of which spring must ,f

be overcome in drawing combustible mixture into the crank case past the valve. In overcoming the tension of such spring, a corresponding drop in the effective suction tending to draw the combustible mixture in the crank case results and a corresponding loss of volume of combustible mixture per stroke of the pistons and consequent loss of power results.

In the construction in which the-combustible mixture is taken through the cylinder and controlled by the movement of the piston, the length of time during which such port is open to the admittance of combustible mixture is necessarily limited and consequently it is impossible to obtain desirable volumetric efciency with such construction.

In the present invention a disc valve 118 is provided for controlling the admittance of the combustible mixture into the crank case. 'I'he valve 118 rotatably encircles the lower end of the crank shaft 97 and overlies the upper surface of the cover 90. The disc 118 is provided with a segmental opening 119, as best illustrated in Figs. 6 and 7, of substantially the same area as the opening 96 in the cover 90. The disc 118 is further provided on its upper surface with a pair of upstanding lugs 120 and 121 which are adapted to order to impart drivingmovement to the disc 118 from the crank shaft 97. The lug 120, as illustrated in Fig. 6, is' sopositioned relatively to the opening 119 that when `the crank shaft is turning in the direction indicated by the arrow 117 in Fig.' 6 and the pistons are at the bottom of their stroke, the leading edge of the opening 119 is in or about to become in overlapping relationship with respect to the near edge of the opening 96. In other words, the moment-that the pistons start 'on their outer travel, the openings 119 and 96 overlap each other and thus provide a clear path for the combustible mixture from the carburetor to enterthe crank case. The openings 96 and 119 are preferably so designed in length that they remain in overlapping relationship until the pistons reach the top or the outer limit of their travel. Furthermore, it will be apparent that w/hen the piston isin its midstroke position durlmaintained in open position during the entire time that a suction is apparent in the crank case.

` It willalso be apparent that it may be desirable in some cases to maintain the intake port open into the crank case for a'short period after the piston has reached the outer limit of travel, and in such cases the openings 119 and 96 may-obviously be varied to accomplish suchresult.

When the crank shaft is turning in the opposite direction to that shown in Fig. 6, or as indicated by the arrow 122 in Fig. 7, it will be obvious that if the lug 120 only were employed, the relation of the openings 119 and 96 would not be correct for proper timing of the entrance of the` combustible mixture into the crank case. For this reason, the lug 121 is provided which cooperates with the adjacent throw of the crank shaft 97, when the engine is turning as indicated by the arrow 122, in thesame manner that the lug 120 Vco cooperates therewith, as previously described when the. engine is turning in the opposite direction. 'This gives a constructionin which it is possible to instantly reverse the direction of rotation of the engine without affecting the relative timing of the same in any manner whatsoever. 'I'he disc 118 being in contact with the upper face of the flange and being separated therefrom .by the usual film of lubricating oil, has sufficient drag to maintain thelug 120 or 121, as the case may be, against the crank shaft during operation oi the engine, and still turns free of the crank shaft when the direction of rotation of the engine is reversed, although separate means may be provided for insuring such action, if desired.

As is commonly the case with the engines of this type, lubrication for the same is provided by mixing the lubricant with the fuel in the fuel tank so that it is fed into the engine with the combustible mixture. The bulk of such lubricant is separated out in the crank case and collects there in appreciable amounts. In accordance with the present invention I am enabled to utilize this fact in connection with the disc 118 to provide a novel and efficient additional lubricating means for the crank shaft and the connecting rods. Due to the fact that the disc 119 is positioned in the bottom ofthe crank case and due to the fact that the edge of the same with considerable force. Taking advantage of this fact I extend the disc 118 into relatively closely adjacent relationship with respect to the cooperating edge of the crank case 25,

as best illustrated in Figs. 8, 9 and 10, and I extend such edges of the crank case 25 so as to bein alignment with the disc 118 throughout the .width of the same. This causes the oil carried to the outer edge of the disc 118 during rotation thereof to build up between its outer edge and the adjacent edge of the crank case I` then provide a recess as at .124 in the adjacent edge of the crank case and opening on to the outer edge of the disc 118. I then connect this recess 124 by an opening 125, connection 126, and tube '127 .to the ,point where I desire the lubricant to be deposited. Such a point may bein connection with the upper main bearing of the crank shaft-97, as is illustrated in Fig. 3, and in which an annular groove 128 is provided in the bushing 99 about the crank shaft 97 and which is connected by means of the connection 132 to the tube 127. 'Ihe lubricant is thus forced by the disc 118 into the recess 124 from which it is conducted through the opening 125 and tube 127 to the groove 128 where it serves to lubricate the inner surface of the bushing 99. This arrangement may also apply to the bushing 98.

I nd that where the pressure of the lubricant thus obtained is not as high as is desired the crank case 25 may be formed with a flange or lip 131 as indicated in Fig. 9, overlapping the upper face of the disc 118 adjacent its outer edge so that the outer edge of the disc 118 is enclosed on three sides. This has the effect of restricting the escape of oil upwardly from the outer edge of the disc 118 and serves to provide a construction which may be likened to the conventional type of centrifugal pump.

The lubricant thus deposited in the groove 128 may work downwardly and again be drawn into vthe crank case and I provide means whereby such lubricant may be caught and employed for lubricating the large ends of the connecting rods in the following manner. Each throw of the crank shaft 97 is provided with a relatively large central blind opening 129 opening on the upper of the crank shaft so that the lubricating oil Each of the openings 129 is connected l.

therein will be thrown by centrifugal force acting upon it because of the rotation of the crank shaft, to the bearing surface. This provides an extremely efficient lubricating system amply adapted to take care of the needs of high speeds desirable to form the throws of the crank shaft to accomplish the same result, and thereby dispense with the additional disc for suchpurpose.

In Fig. 2 is illustrated the manner of connecting the upper and lower portions of the drive shaft housing together as well as the upper and lower portions of the drive shaft itself. As indicated in Fig. 2 the upper end of'the lower shaft housing portion 28 is provided with a. top wall 40 and the lower end of the upper drive shaft portion 27 is provided with a flange 41 commensurate in size and shape with the wall 40. Screws such as 42 threading down through the flange 41 andinto the wall 40 serve to secure the two portions together. For preserving alignment of the two housing portions a pilot 43 is formed on the upper face of the wall 40 and a corresponding recess is formed in the flange 41 to receive it.

As also illustrated in Fig. 2 the drive shaft is formed in upper and lower sections 44 and 45 respectively. The upper end of the section 45 is journaled in a bearing `46 socketed in the wall 40 of the lower drive shaft housing portion 28. The drive shaft section 45 is enlarged above the bearing 46 to provide an internally splined cup 47, 1n

which the lower splined end 48 of the upper drive shaft section 44 is non-rotatably received. With this construction, by forming the bearing 46 to take both radial and thrust loads, a novel and eflcient means for supporting the weight of the crank shaft of the engine is provided. It will be apparent that, for obvious reasons, it is desirable that the disc 118 within the crank case 25 be free of the weight of the crank shaft and proportional part of the connecting rod load when rotating, for otherwise undue friction between the disc 118 and the corresponding end wall o f the crank case might develop with resulting undesirable wear. Accordingly, the upper end of the drive shaft section 44 which is splinedr for engagement with the splined opening 102 in the crank shaft 97, is provided with a shoulder 50 which contacts with the lower end of the bearing 97 and serves to carry the weight of the crank shaft therethrough. The length of the drive shaft section 44 is such that when the enlarged cup-like end 47 on the drive shaft section 45 is seated on the bearing 46, and the lower end of the drive shaft section 44 is seated in the bottom of the cup-shaped portion47, the lower throw of the crank shaft is supported at a distance above the upper face of the cap 90 an amount in excess of the thickness of the disc 118. The disc 118 is thus freed of all weight except its own, and preferably being of relatively light construction is enabled to run at relatively high speed with substantially no resulting heating or wear. Furthermore, in supporting the weight of the crank shaft and the corresponding portion of the weight of the connecting rods 104 through the bearing 46, and the bearing 46 being positioned in relatively close thermal relationship to that portion of the outboard motor actually submerged in the water during operation, overheating of the bearing 46 is consequently eliminated.

At 174 in Figs. 1 and 3 there is indicated a connection which leads into the lower portion of the cylinder water jacket 175. The upper portions of the water jacket 175 are provided with connections 176. These connections are for connection with a convenient cooling system.

Formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

1. In combination with an internal combustion engine having a crank cas'e and a. vertically disposed crank shaft therein, a disc in the bottom of said crank case rotatable with said crank shaft, said disc extending into relatively close relationship with respect to the walls of said crank case, a recess in the inner walls of said crank case in the plane of said disc and opening onto the outer face thereof, and a passage leading from said recess to a bearing surface of said engine.

2. In aninternal combustion engine having a crank case and a vertically disposed crank shaft therein, said crank shaft being provided with an eccentric crank pin, an upwardly opening blind opening in said crank pin, and a passage extending through the walls of said crank pin from said opening to the outer face of said crank pin and disposed on the outer side of said crank pin from the axis of said crank shaft.

3. In an internal combustion engine of the twocycle type provided with a crank case and a crank shaft, said crank case being provided with an opening connected with a carburetor, a disc within saidcrank case rotatable with said crank shaft and overlying said opening, said disc being Vprovided with an opening cooperating with the rst mentioned opening to control the flow of combustible mixture from said carburetor into said l crank case, and means for driving said disc from said crank shaft operable automatically to vary the rotatable position of said disc relative to said crank shaft upon reversal of the direction of rotation of the latter.

4. In combination with an internal combustion engine of the two-cycle type provided with a crank case and a crank shaft, said crank case being provided with an opening therein connected with a carburetor, a disc rotatably mounted on said crank case overlying said opening and provided with an opening co-operable with the first mentioned opening, and a pair of lugs on said disc cooperating with said crank shaft to drive said disc from said crank shaft, said lugs being so disposed as to cause overlapping of said openings on the suction stroke only of said engine regardless of the direction of rotation of said crankshaft.

5. In combination with an internal combustion engine having a crank case and a vertically disposed crank shaft therein, said shaft having a bearing in said crank case, an intake port in the bottom of said base, a disc rotating with said crank shaft overlying said port and provided with a second port for controlling the flow of combustible mixture through the first mentioned port, said disc being driven from said crank shaft, means adjacent the periphery of said disc for` collecting oil thrown off of said disc due to centrifugal forces acting lthereon, and a duct connecting said means and said bearing.

6. In an internal combustion engine of the twocycle type, a crank case, a vertically disposed crank shaft journaled in said crank case, said crank case being provided with an intake port opening in the bottom Wall thereof, a ported disc overlying said port opening and adapted to controlthe flow of combustible mixture therethrough into said crank case, means for driving said disc from said crank shaft, said disc resting on said bottom wall free of the weight of said crank shaft, and means below said disc for supporting the weight of said crank shaft.

'7. In an internal combustion engine of the twocycle type, a crank case, a vertically disposed crank shaft joumaled in said crank case, said crank case being provided with an intake port opening in the bottom wall thereof, a ported disc overlying said port opening' and adapted to control the flow of combustible mixture therethrough into said crank case, means for driving said disc from said crank shaft, and means for supporting the weight of said crank shaft independently of and from a point below said disc.

8. In an internal combustion engine, in combination, a crank case having an opening in the lower wall thereof, a vertically disposed crank shaft rotatable in said crank case, a disc concentric with said crank shaft and resting on said lower wall Within said crank case, means for driving said disc in unison with said crank shaft, said disc having an opening therein co-operating with said opening in said lower wall to control the flow of gas into said crank case, a housing member projecting downwardly from said lower wall, a bearing carried at the lower end` of said housing member, and means for supporting said crank shaft from said bearing.

9. In an internal combustion engine, in combination, a crank case having an opening in the lower wall thereof, a vertically disposed crank shaft rotatable in said crank case, a disc concentric with said crank shaft and resting on said lower wall within said crank case, means for' driving Said disc in unison with said crank shaft, said disc having an opening therein co-operating with said opening in said lower wall to controll the flow of gas into said crank case, a housing member projecting downwardly from said lower wall, a bearing carried at the lower end of said housing member, and means for supporting said crank shaft from said bearing with the throws of said crank shaft in spaced relation with relll 

